Ethyl 2-pyridinecarboxylate → 1-(2,3-Dihydrobenzo[b][1,4]dioxin-6-yl)-3-(pyridin-2-yl)propane-1,3-dione

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Reaktionsschritte

A solution of 1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)ethanone (XV) (1 eq) in THF was added slowly to a suspension of NaH (1.5 eq) in THF stirred under nitrogen at room temperature. The solution was further allowed to stir at room temperature until the evolution of gas was ceased. Ethyl picolinate (XIX) (1.1 eq) was added to the solution and refluxed overnight under nitrogen. The solution was cooled, poured into ice water and extracted with ethyl acetate. The organic layer was dried over MgSO4, filtered and concentrated under vacuum. The crude product was purified by column chromatography over silica gel to produce 1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-3-(pyridin-2-yl)propane-1,3-dione 15 as a yellow solid (71% yield), 1H NMR (CDCl3, 400 MHz): δ ppm 4.13-4.43 (m, 4H), 6.94 (d, J=8.31 Hz, 1H), 7.42 (m, 1H), 7.44 (m, 1H) 7.59 (m, 2H), 7.85 (m, 1H), 8.14 (d, J=7.81, 1H), 8.65 (m, 1H); ESIMS found C16H13NO4 m/z 284 (M+H).

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